Thursday, August 2, 2007

Mosquitoes with West Nile found in Medford

By Stephen Smith, Globe Staff

For the third time this summer, mosquitoes infected with West Nile virus have been found in Massachusetts, public health authorities announced today. The latest batch of disease-carrying insects was collected in Medford. Earlier, mosquitoes carrying the potentially lethal virus were discovered in Berkley and Marlborough.

Traditionally, West Nile begins circulating widely in mosquitoes in August, increasing the threat of infections in people. No human cases of West Nile have been reported this year in Massachusetts; last year, three people contracted the illness in Massachusetts; all survived.

So far this year, most of the 185 human cases of the disease in the United States have been reported west of the Mississippi River. California has the most, with 42. In the most severe cases, the infection can cause a high fever, headache, neck stiffness, stupor, coma, tremors, convulsions, muscle weakness, and paralysis. The US Centers for Disease Control and Prevention estimates that one of every 150 people infected with West Nile develops severe symptoms.

To avoid contact with infected mosquitoes, the Massachusetts Department of Public Health recommends limiting outdoor activities from dusk to dawn, peak biting times for mosquitoes. Otherwise, wear as much clothing as comfortable and apply insect repellent such as DEET, permethrin, picaridin, or oil of lemon eucalyptus.

DEET should not be used on infants under the age of 2 months and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children under 3 years old.